CVE-2026-40478 — AI Deep Analysis Summary

🚨 **Essence**: Thymeleaf template engine has a security bypass flaw in its expression execution mechanism.…

🛡️ **Root Cause**: **CWE-917** (Improper Neutralization of Special Elements used in a Dynamic Expression).…

📦 **Affected**: **Thymeleaf** (Java Template Engine). <br>📅 **Versions**: **3.1.3.RELEASE** and all earlier versions. <br>🏢 **Vendor**: thymeleaf.

💀 **Capabilities**: High Impact (CVSS H:H:H). <br>🔓 **Privileges**: Can likely achieve **Remote Code Execution (RCE)** or full system compromise.…

🔑 **Threshold**: **High** (AC:H). <br>🚫 **Auth**: No privileges required (PR:N). <br>👀 **UI**: No user interaction needed (UI:N). <br>🌐 **Vector**: Network (AV:N).…

📜 **Public Exp**: **No** public PoC or exploit code listed in the data (pocs: []). <br>🔒 **Status**: Reference link provided (GHSA-xjw8-8c5c-9r79) confirms the advisory, but no wild exploitation is confirmed yet.

🔍 **Self-Check**: Scan for **Thymeleaf 3.1.3 or older** in your Java dependencies. <br>🧪 **Test**: Look for usage of Thymeleaf expressions in user-controlled inputs.…

🛠️ **Fix**: Upgrade to a version **newer than 3.1.3.RELEASE**. <br>🔗 **Official Source**: Check the GitHub Security Advisory (GHSA-xjw8-8c5c-9r79) for the patched version details.

🚧 **Workaround**: If patching is impossible, **strictly sanitize** all user inputs before passing them to Thymeleaf expressions. <br>🚫 **Disable**: Disable dynamic expression evaluation if not required.…

🔥 **Urgency**: **High Priority**. <br>📉 **CVSS**: High severity (C:H, I:H, A:H). <br>⏳ **Action**: Patch immediately upon upgrading to a safe version.…